Electric furnace.



No. 885,745. PATENTED APR. 28 1908. P. GIRODI ELECTRIC FURNACE.

APPLICATION FILED nnc.2o,19o5.

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YQUFW tially ings.

UNITED srarns Parana PAUL GIROD, OF UGTNE, FRANCE.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented. April 22%,

Application filed December 20, 1905. Serial No. 292,618.'

electric furnace of the type disclosed in my French patent 329822 andthe certificate oi addition thereto, N o. 3425.

The present invention has for its object to provide an electric furnacebymeans of which a plurality of objects such, for example, as crucibles,may be heated in one furnace.

In the accompanying drawings, I have illustrated one embodiment of theinvention.

In the drawings Figure 1 is a Vertical longi tudinal section of thefurnace; and Fig. 2 a section on the line A-A of Fig. 1.

Referring to the drawin s, 2 indicates a receptacle which forms theeating chamber, within which may be placed a piurality of objects to beheated, for example, the series of crucibles, 1, indicated in thedrawings.

Thereceptacle 2 is shown as substantially rectangular, with twonarrowextensions 8, one at each end. The said receptacle is surrounded byinsulating masonry 6 arranged to leave a space between its inner wallsand the outer walls of the receptacle, which space is filled with asuitable resistance material, for example, a pulverulent gra hite composition, as ex lained in my said I iench patent 329822, an thecertificate of'addition 3425 The extensions 8, serve to transmit theweight of the receptacle to the masonry, thus leavin the resistancematerial 5 substanee from pressure due to such Weight. The receptaclebottom may be solid, but it is advantageous to provide perforations 4,to allow the heat frorri the heating resistance 5 to radiate {reel intothe chamber 2.

The furnace as pole pieces 9, 9, 10 and 10 with which the terminals ofthe electric cir;

cuit are connected, as indicated in the draw- The furnace is coveredwith refracto plates 7 which can be removed easily in or er to allow theinsertion or removal of the crucibles.

The resistant heatirig mass may be arranged in any of the waysyindicatedin the said French I atent and certificate oi addi' tion, but pre erablyin such a manner as to completely surround the chan'iber, the currentbeing led into and out of the same side of the furnace. This resistancemay he civided into sections and grouped together as desirable, in sucha manner as to produce a regular heating, the current traversing theheating resistances both. at the sides and at the ends in the directionsof the planes of said sides and ends, owing to the manner ofintroduction the current, as indicated by the positive and negativesigns on the drawings.

Having thus fully described my invention, What I claim, 1s:*

l. in. an electric furnace, the combine tion, with'a receptacle forminga chamber arranged to receive a plurah'y of objects to be heated, of amass cf resistance material arranged in layers in contact with thesides, ends and bottom of said receptacle, and a plurality of polepieces of opposite polaritychamber arranged to receive a plurality ofobiects to be heated, said receptacle having a perforated bottom, ofresistance material in contact witlri the outer waits l bottom of saidreceptacle, means for conoucting cur rent to said resistance material,and a cover for the receptacle, said cover being formed in sections.

In testimony whereof I have signed this specification in the presence oitwo subscribing Witnesses.

' l fitnesses

